Owing to increase in capacity of movie recording devices and widespread use of fast/broad-band networks in recent years, a large amount of movies have been handled more often than ever, and therefore a manner for efficiently retrieving and managing movies has been required.
Intrinsically, a movie is searched for details of scenes contained therein. For such searching or retrieval, it is necessary to replay successively the movie and determine the details. However, this is not practical for a large amount of movies. Therefore, description information describing details of movies are prepared in advance for each movie so that the movie retrieval can be performed based on the description information.
As disclosed in Japanese Patent Laying-Open Nos. 05-282379 (patent reference 1) and 08-110912 (patent reference 2), the description information is often configured as data having a tree structure for allowing easy retrieval.
FIG. 1 illustrates an example of conventional description information.
Referring to FIG. 1, a whole movie is formed of four scenes [1]-[4]. For each scene, the description information describes time information (start time and length) of the scene, a title of the scene and actors appearing in the scene.
Based on the above description information, a user can know that an actor “Keiko KUBO” appears in a scene [1], and can reproduce the scene [1] in which “Keiko KUBO” appears, from the whole movie according to the time information of “start time: 00:00:00, length: 3 mins” of the scene [1]. As described above, the description information is very effective at the movie retrieval.
FIG. 2 illustrates details of the description information data illustrated in FIG. 1.
Referring to FIG. 2, the actual description information is given as data strings, and each of items in each scene is individually described as the data. The individual data describing details of each item such as names of actors will be referred to as a “keyword”.
Patent reference 1: Japanese Patent Laying-Open No. 05-282379
Patent reference 2: Japanese Patent Laying-Open No. 08-110912